A combined model–observation approach to estimate historic gridded fields of PM2.5 mass and species concentrations

This paper introduces a methodology for estimating gridded fields of total and speciated fine particulate matter (PM_2.5) concentrations for time periods and regions not covered by observational data. The methodology is based on performing long-term regional scale meteorological and air quality simulations and then integrating these simulations with available observational data. To illustrate this methodology, we present an application in which year-round simulations with a meteorological model (the National Center for Atmospheric Research/Penn State Mesoscale Model, hereafter referred to as MM5) and a photochemical air quality model (the Community Multiscale Air Quality Model, hereafter referred to as CMAQ) have been performed over the northeastern United States for 1988–2005. Model evaluation results for total PM_2.5 mass and individual species for the time period from 2000 to 2005 show that model performance varies by species, season, and location. Therefore, an approach is developed to adjust CMAQ output with factors based on these three variables. The adjusted model values for total PM_2.5 mass for 2000–2005 are compared against independent measurements not utilized for the adjustment approach. This comparison reveals that the adjusted model values have a lower root mean square error (RMSE) and higher correlation coefficients than the original model values. Furthermore, the PM_2.5 estimates from these adjusted model values are compared against an alternate method for estimating historic PM_2.5 values that is based on PM_2.5/PM₁₀ ratios calculated at co-located monitors. Results reveal that both methods yield estimates of historic PM_2.5 mass that are broadly consistent; however, the adjusted CMAQ values provide greater spatial coverage and information for PM_2.5 species in addition to total PM_2.5 mass. Finally, strengths and limitations of the proposed approach are discussed in the context of potential uses of this method.     

Biological responses to sediment remediation based on thin layer placement near a former pulp mill in Ward Cove, AK (USA)

In 2001, 28 acres of the bottom of Ward Cove, AK (USA) were remediated using thin layer placement, to enhance the natural recovery of contaminated sediments. The remediated areas were part of an 80-acre area of concern identified offshore from the site of a former sulfite pulp mill. The primary chemicals of concern were those commonly associated with organic enrichment near pulp mills: ammonia and 4-methylphenol. The primary remedial objectives were to reduce the toxicity of the contaminated sediments and to stimulate colonization of the remediated areas by benthic macroinvertebrates. In 2004, the initial monitoring event for the remediated areas was conducted, and included evaluations of physical/chemical sediment variables (i.e., total organic carbon, grain size distribution, ammonia, and 4-methylphenol), sediment toxicity (i.e., using the 10-day amphipod survival test with Eohaustorius estuarius), and in situ benthic macroinvertebrate communities. Results of the monitoring event showed that conditions in the remediated areas had improved considerably in the 3 years since thin layer placement had occurred. At most stations, concentrations of both ammonia and 4-methylphenol were very low, and amphipod survival was >or=90%. In addition, benthic macroinvertebrates appeared to be rapidly colonizing the remediated areas, based on evaluations of several community metrics (i.e., taxa richness, diversity, and dominance), as well as key indicator species of organic enrichment and associated transitional areas (i.e., primarily the polychaetes Capitella capitata and Nephtys cornuta, and the bivalve molluscs Axinopsida serricata and Parvilucina tenuisculpta). In general, colonization was consistent with the patterns identified for areas recovering from organic enrichment on the continental shelf of southern California and elsewhere. Based on these results, thin layer placement was considered successful in enhancing the natural recovery of the remediated sediments in Ward Cove.     

Editorial: Special issue on composite sampling

Environmental and Ecological Statistics -     

The effect of resuspending sediment contaminated with antifouling paint particles containing Irgarol 1051 on the marine macrophyte Ulva intestinalis

The effect of resuspending sediment contaminated with Irgarol 1051 based antifouling paint particles on the green macroalga Ulva intestinalis was examined. U. intestinalis was also exposed to sediment spiked with Irgarol 1051. The macroalga were exposed over 21 days to the resuspension of sediments containing 61.2 mg kg(-1) of antifouling paint particles containing Irgarol 1051 that provided aqueous Irgarol 1051 concentrations of approximately 0.3 microg l(-1), Irgarol 1051 and appropriate controls. The growth response was compared with that for 'clean' sediment. Resuspension of sediment was associated with reduced growth when compared to seawater alone. Resuspension of sediment spiked with Irgarol 1051 was associated with a greater reduction in growth, with growth being significantly reduced when sediment containing antifouling paint particles was resuspended. The data suggest that the prolonged disturbance of sediments containing antifouling paint particles in marinas represents a potential and as yet unquantified hazard to photosynthetic organisms.     

Tyrannical Spaces: young people, bullying and urban neighbourhoods

We consider the street experiences of a group of urban children living in a large East Midlands town in the UK. Our attention focuses upon an issue that has seldom been examined, neighbourhood bullying. We highlight how some children, through their propinquity within neighbourhood spaces, clash and collide to such an extent that their experiences of a locality become severely blighted. For these unfortunate young people local environments are tyrannical spaces, defined in terms of 'no-go areas', danger and threat. These are not remarkable geographies, however, and we suggest that like many school environments, where bullying has increasingly been recognised and disclosed, within many localities there is a 'hidden' geography of fear waiting to be uncovered. The paper is organised into five parts: first, we briefly examine the concept of bullying, particularly in relation to young people in schools; secondly, we extend these ideas into a neighbourhood context drawing upon recent ideas of 'self', 'other' and microgeographies; thirdly, we outline the research project from which this article emerges; fourthly, we look at some empirical evidence from an urban case study that draws attention to the form and consequences of neighbourhood bullying; lastly, we discuss the relevance of these findings to future policy and practice, particularly in relation to the management of neighbourhood spaces. We propose that systematically applied local strategies to tackle bullying within neighbourhoods are needed, particularly those which engage young people and adults together through a whole community approach.     

Atmospheric deposition of polycyclic aromatic hydrocarbons near New England coastal waters

Wet and dry deposition of polycyclic aromatic hydrocarbons (PAHs) was measured at Nahant, Massachusetts, a peninsula jutting into Massachusetts Bay and Wolf Neck, a peninsula jutting into Casco Bay, Maine. Wet deposition (rain and snow) was collected in a funnel which drains into a shielded, temperature controlled receiving bottle. Dry deposition of gaseous and particulate PAHs was collected onto an exposed water surface. PAHs were analyzed by solid phase extraction and gas chromatography-mass spectrometry. Sixteen PAH species were analyzed, ranging from acenaphthylene to coronene. The mean wet deposition rate of the sum of the 16 species is 720 ng m⁻² cm⁻¹ precipitation at Nahant, and 831 ng m⁻² cm⁻¹ precipitation at Wolf Neck. Wet deposition is attributed to regional PAH emitting sources. Storm patterns appear to bring somewhat higher wet deposition of PAHs to Wolf Neck than to Nahant. The mean dry deposition rate is 95 ng m⁻² h⁻¹ at Nahant and 9.3 ng m⁻² h⁻¹ at Wolf Neck. The large difference is attributed to the fact that Nahant is close to the urban-industrial metropolitan Boston area and Logan International Airport, whereas Wolf Neck has no major PAH-emitting sources nearby. Individual measurements have an error bracket of ±30%. The Chemical Mass Balance model was used to apportion the dry deposition to source categories. At Nahant, nine samples gave valid statistical attributes with a mean apportionment: jet exhaust 35%, gasoline fueled vehicles 32%, diesel fueled vehicles 17%, wood combustion 13%, others 3%. At Wolf Neck, six samples yielded a mean apportionment: jet exhaust 30%, gasoline vehicles 28%, diesel vehicles 18%, wood combustion 16%, others 8%. There is a considerable variation between the samples. The apportionment is greatly dependent on the quality and selection of the model inputs, i.e. source signatures, which for PAHs are questionable.     

Key role for nuclear energy in global biodiversity conservation

Modern society uses massive amounts of energy. Usage rises as population and affluence increase, and energy production and use often have an impact on biodiversity or natural areas. To avoid a business‐as‐usual dependence on coal, oil, and gas over the coming decades, society must map out a future energy mix that incorporates alternative sources. This exercise can lead to radically different opinions on what a sustainable energy portfolio might entail, so an objective assessment of the relative costs and benefits of different energy sources is required. We evaluated the land use, emissions, climate, and cost implications of 3 published but divergent storylines for future energy production, none of which was optimal for all environmental and economic indicators. Using multicriteria decision‐making analysis, we ranked 7 major electricity‐generation sources (coal, gas, nuclear, biomass, hydro, wind, and solar) based on costs and benefits and tested the sensitivity of the rankings to biases stemming from contrasting philosophical ideals. Irrespective of weightings, nuclear and wind energy had the highest benefit‐to‐cost ratio. Although the environmental movement has historically rejected the nuclear energy option, new‐generation reactor technologies that fully recycle waste and incorporate passive safety systems might resolve their concerns and ought to be more widely understood. Because there is no perfect energy source however, conservation professionals ultimately need to take an evidence‐based approach to consider carefully the integrated effects of energy mixes on biodiversity conservation. Trade‐offs and compromises are inevitable and require advocating energy mixes that minimize net environmental damage. Society cannot afford to risk wholesale failure to address energy‐related biodiversity impacts because of preconceived notions and ideals.     

Western Land Managers will Need all Available Tools for Adapting to Climate Change,Including Grazing: A Critique of Beschta et al.

In a previous article, Beschta et al. (Environ Manag 51(2):474–491, 2013) argue that grazing by large ungulates (both native and domestic) should be eliminated or greatly reduced on western public lands to reduce potential climate change impacts. The authors did not present a balanced synthesis of the scientific literature, and their publication is more of an opinion article. Their conclusions do not reflect the complexities associated with herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a challenge. Legacy effects of uncontrolled grazing during the homestead era further complicate analysis of current grazing impacts. Interactions of climate change and grazing will depend on the specific situation. For example, increasing atmospheric CO₂ and temperatures may increase accumulation of fine fuels (primarily grasses) and thus increase wildfire risk. Prescribed grazing by livestock is one of the few management tools available for reducing fine fuel accumulation. While there are certainly points on the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal. Broad scale reduction of domestic and wild herbivores to help native plant communities cope with climate change will be unnecessary because over the past 20–50 years land managers have actively sought to bring populations of native and domestic herbivores in balance with the potential of vegetation and soils. To cope with a changing climate, land managers will need access to all available vegetation management tools, including grazing.